In continuous casting plants of modern construction consisting of a vertically arranged mold and a guiding zone for the strand arranged to follow the mold, where the guiding zone is arc-shaped and makes a transition to the horizontal, it is of great importance in achieving good quality continuously cast strands that the strand be guided with exactness between its supporting, guiding and bending rollers. It is therefore necessary to compare rapidly and objectively the graphically determined or theoretical machine profile -- i.e. the nominal machine profile, with the actual machine profile as it exists after a period of operation or after repairs, so that individual rollers and/or parts of the roller conveyor, e.g. in the bending or straightening zone of the continuous casting machine, may be adjusted accordingly. Hitherto, it has been necessary to measure in laborious and time-consuming detail, the clearance between the individual roller pairs in several places and to record all the data gained. Then, after a comparison with the nominal machine profile, it was possible to proceed to the required adjustment work. In a continuous operation of a continuous casting machine a lot of time is needed for carrying out this work. Apart from this aspect it has hitherto not been possible to find deviations, i.e. a discontinuity, between individual roller conveyer parts, which form the conveyor. As a consequence of such a discontinuity between parts of the roller conveyor, cracks may occur in the casting. Moreover, when there are irregular roller distances, the withdrawing forces for the casting increase considerably and under extreme circumstances the strand might even break. It is even more difficult, if not altogether impossible, to determine exactly and rapidly the curvature or curvature alteration in the transition zone from a vertical guiding path to a circular arc and/or from a circular arc to a horizontal guiding path, and to compare this curvature or curvature alteration with the nominal profile.